1. Field of the Invention
The present invention relates to the use of machine-readable symbols with high information density and capacity for recording document information, and more particularly to the reproduction of such document information in a unique form.
2. Description of the Prior Art
Encoded symbols, such as the well-known UPC bar code symbol, have gained wide use in many industries as a tool to increase speed and accuracy of data capture in a vast number of diverse applications, such as point-of-sale item pricing, inventory control, article tracking, and so on.
The traditional bar code symbols are quite limited, however, in the amount of encoded data or information they can contain. Thus, in many applications, the bar code symbol borne by an item is simply an address to a database where information regarding the item is stored, such as a plain language descriptor of the item, price, etc.
The above-cited, related application Ser. No. 07/461,881 discloses a two dimensional bar code symbol which has high information density and capacity capabilities. This symbol, known as the PDF417 bar code symbol, can serve as a portable data file containing all the information necessary to identify and describe the item to which it is applied. In fact, the PDF417 symbol has sufficient information density and capacity to represent as many as 500 characters per square inch of ASCII data. Thus, a relatively small number of PDF417 symbols, and in some cases a single PDF417 symbol can be encoded with alphanumeric text filling a letter-size document, as disclosed in the above-cited, related application Ser. No. 08/123,955.